usbsprl

- Prolific PL2303 USB to serial converter driver

Synopsis

#include <fcntl.h>

#include <sys/termio.h>

usbsprl@unit

Description

The usbsprl driver is a loadable STREAMS and USBA (Solaris USB
architecture) compliant client driver that provides basic asynchronous communication support for
Prolific PL2303 USB-to-serial converters. Supported devices include PL2303H, PL2303HX and PL2303X.
Serial device streams are built with appropriate modules that are pushed atop the
usbsprl driver by the autopush(1M) facility.

The usbsprl module supports the termio(7I) device control functions specified by flags
in the c_cflag word of the termios structure, and by the IGNBRK,
IGNPAR, PARMRK and INPCK flags in the c_iflag word of the
termios structure. All other termio(7I) functions must be performed by STREAMS modules pushed
atop the driver. When a device is opened, the ldterm(7M) and ttcompat(7M)
STREAMS modules are automatically pushed on top of the stream, providing
the standard termio(7I) interface.

Use device logical names /dev/term/[0-9]* to access the serial
ports. These names are typically used to provide a logical access point
for a dial-in line that is used with a modem.

A special feature (controlled by the minor device number) is available that
enables a single tty line to be connected to a modem and
used for incoming and outgoing calls. By accessing through device logical name
/dev/cua/[0-9]*, you can open a port without the carrier detect signal being
asserted, either through hardware or an equivalent software mechanism. These devices are
commonly known as 'dial-out' lines.

APPLICATION PROGRAMMING INTERFACE

A dial-in line can be opened only if the corresponding dial-out line
is closed. A blocking /dev/term open waits until the /dev/cua line is
closed (which drops Data Terminal Ready, after which Carrier Detect usually drops
as well) and carrier is detected again. A non-blocking /dev/term open returns
an error if the /dev/cua is open.

If the /dev/term line is opened successfully (usually only when
carrier is recognized on the modem), the corresponding /dev/cua line cannot
be opened. This allows a modem and port to be used
for dial-in (by enabling the line for login in /etc/inittab) or dial-out
(by tip(1), or uucp(1C)) when no one is logged in on the
line.

Device hot-removal is functionally equivalent to a modem disconnect event, as
defined in termio(7I).

ioctls

The usbsprl driver supports the standard set of termio(7I) ioctl
calls.

Input and output line speeds can be set to the following baud
rates: 75, 150, 300, 600, 1200, 1800, 2400, 4800, 9600, 19200,
38400, 57600, 115200, 230400 or 460800. Input and output line speeds
cannot be set independently. For example, when the output speed is set,
the input speed is automatically set to the same speed.

Errors

An open() fails under the following conditions:

ENXIO

The unit being opened does not exist.

EBUSY

The /dev/cua (dial-out) device is being opened while the /dev/term (dial-in device) is open, or the dial-in device is being opened with a no-delay open while the dial-out device is open.

EBUSY

The unit has been marked as exclusive-use by another process with a TIOCEXCL ioctl() call.